GM bulletin PIE0788C
What it saysThis engineering information (EI) closure ends the need for gathering further information from technicians in regard to MIL illuminated on DIC to correct BET and BEV3 Ultium Packs Setting Moving Average Voltage… NHTSA’s full summary ↓
GM filed this with NHTSA as a service bulletin dated Jun 28, 2024, received Jul 18, 2024, about the electrical system. It names 8 model years across Chevrolet, GMC and Cadillac (2022–2024). A service bulletin is not a safety recall: it is the manufacturer telling its dealers how to diagnose or repair a condition, and whether the work is paid for depends on the warranty in force. Quoting the number at a service desk can save a diagnosis.
One page for every brand it was filed under. Each brand’s bulletins: Chevrolet · GMC · Cadillac.
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What the bulletin says
Source: NHTSA's summary of the manufacturer's communicationThis engineering information (EI) closure ends the need for gathering further information from technicians in regard to MIL illuminated on DIC to correct BET and BEV3 Ultium Packs Setting Moving Average Voltage Detection (MAVD) and Delta Voltage Rest Period (DVRP) Fault Codes.
Trouble codes it names: U2B7A U2B98 U2B99 U2B9A U2B9B U2B9C U2B9D U2B9E U2B9F U3620 U3621 U3622 U3623 U3624 U3625 U3626 U3627 U3628 U3629 U362A U362B U362C U362D U362E U362F U3630 U3631 U3632 U3633 U3634 U3635 U3636 U3637 U3638 U3639 U363A U363B U363C U363D U363E all 40 read from the document itself; NHTSA’s summary names none
Document filed under this number
| Document | Kind | Dated | NHTSA id | At NHTSA |
|---|---|---|---|---|
| PIE0788C | Service bulletin | Jun 28, 2024 | 11004943 | PDF, 66 KB |
The summary is NHTSA’s abstract of the document, as filed under 49 CFR 579.5. One communication is usually filed as several documents — the bulletin, a dealer notice, an owner letter — and the number on any of them finds this page. A PDF link is shown only once NHTSA’s own server has been seen to serve that document; the rest are checked over the following nights. Quote the number at a service desk; it is what the dealer’s system is keyed on.
Model years it names
Source: as the manufacturer filed themChevrolet 3 model years
GMC 3 model years
Also filed against model years this site has no page for: 2022 GMC Hummer EV Pickup.
Cadillac 2 model years
A vehicle page’s bulletin list shows the newest few communications filed against that model year; the count there is every one.
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What owners reported
Source: NHTSA complaint databaseOwners of the 7 model years this bulletin names have filed 800 complaints with NHTSA since 2015. 205 of them name Electrical System, Fuel/Propulsion System — the same broad component group this bulletin is filed under. NHTSA groups complaints coarsely, so that means the same area of the vehicle, not necessarily the same fault.
The entire left portion of the screen became inoperable and remained a black screen despite attempts to reset the system. The left side of the screen contains information such as gear selection, speedometer, lane keep assist, and many other important information. There is no other way to see what speed you are going besides this screen.
2023 Cadillac Lyriq · Electrical System · filed with NHTSA Dec 11, 2024 · ODI 11630145
On February 4, 2026, my wife drove to the bank, a trip of about 10 to 15 minutes, and turned off the car at the ATM. When she tried to leave, the vehicle wouldn't start. After a while, she opened and closed the door and locked and unlocked the car twice with the remote control, and the vehicle started and she was able to drive, but all…
2024 Chevrolet Blazer · Electrical System · filed with NHTSA Feb 5, 2026 · ODI 11715867
On , about 400 miles into our trip heading South on , the Engine Reduced Power Warning came on. We were in the fast lane traveling at 70 MPH,the car immediately slowed to about 30 mph. There was no prior warning or check engine light. Vehicles behind us had to swerved and change lanes to avoid hitting us.
2024 Chevrolet Equinox · Fuel/Propulsion System · filed with NHTSA Jul 8, 2025 · ODI 11672055
In depth: 2024 Chevrolet Silverado electrical problems →
A complaint is one owner’s account, not a defect finding, and a bulletin is not a recall. Nothing here says this bulletin was issued because of these complaints, or that the repair it describes fixed them. Complaint files on this site begin in 2015.
More bulletins about the electrical system
Source: same model, same component group385 other manufacturer communications filed against these GM models under the same component group (electrical system), newest first. The eight newest are listed; the rest are on the Chevrolet list.
| Number | Kind | Dated | NHTSA’s summary |
|---|---|---|---|
| N262565450 | Service campaign | Oct 26, 2026 | Customer Satisfaction Program. Certain vehicles listed above may have a condition in which remanufactured high voltage battery packs were b… |
| N252514001 | Service campaign | Oct 5, 2026 | Service Update. Certain vehicles listed above may enable the new King Crab Feature through OTA programming or programming at the dealer. De… |
| N242468490-02 | Service campaign | May 28, 2026 | Certain vehicles may have missing cavity plugs from the rear chassis harness electrical connector. Dealers are to inspect the rear chassis h… |
| N252529080 | Service campaign | Apr 1, 2026 | Service Update. Certain vehicles listed above may be missing a high voltage header plug on the RESS battery pack drive motor connector. Dea… |
| N252515590 | Service campaign | Jan 27, 2026 | Certain vehicles listed above, may have a condition in which the body-to-chassis ground strap may be corroded. Dealers will replace the grou… |
| 24-NA-166 | Service bulletin | Nov 7, 2025 | This technical bulletin provides repair information to correct a customer concern of DTC C1171 C1172 C1173 C1174 Tire Pressure Monitor Senso… |
| 24-NA-227 | Service bulletin | Nov 4, 2025 | This technical bulletin provides repair information to correct a customer concern of Vibration Rattle or Boom at 1800 to 2000 RPM. |
| 25-NA-061 | Service bulletin | Oct 3, 2025 | This technical bulletin provides a procedure to correct the condition of Driver or Passenger Rear Door Handle Will Not Fold In. |
Quote the number at the service desk. It is what the dealer’s system is keyed on.
Every manufacturer communication NHTSA holds for Chevrolet, GMC and Cadillac, by the number printed on the letter.
Common questions
Source: NHTSA, 49 CFR 579.5Is GM PIE0788C a recall?
No. A service bulletin is a manufacturer communication filed with NHTSA under 49 CFR 579.5; a safety recall carries an NHTSA campaign number (two digits, a letter, six digits) and a federal duty to repair for free. Check the vehicle’s recalls by VIN at nhtsa.gov/recalls, or on its page here.
Is the PIE0788C repair free?
Not automatically. A service bulletin describes how to diagnose or repair a condition; who pays depends on the warranty in force, any extension, and the dealer. Quoting the number can save a diagnosis either way. Every GM warranty extension on file lists the ones GM has filed.
Which vehicles does PIE0788C cover?
The manufacturer filed it against 8 model years across 3 brands (Chevrolet, GMC and Cadillac): 2024 Cadillac Lyriq, 2023 Cadillac Lyriq, 2024 Chevrolet Blazer, 2024 Chevrolet Equinox, 2024 Chevrolet Silverado, 2024 GMC Hummer EV and more. Whether one particular vehicle is affected is a matter of its VIN and its build, not its model year alone.